Start by grating the peel from the lemon in to a bowl. Whisk together the eggs and sugar until light fluffy and then add the vanilla. Squeeze in the juice from the lemon.
Sieve together the flour, baking soda and salt in a separate bowl and then combine with the sugar and egg mixture.
Melt down the butter with the milk and then add to your mixture.
Mix in the lemon peel and the poppy seeds.
Grease two baking tins and pour half of the batter in to each.
Place in to greased baking tins and bake in an oven set to 350' for 10 minutes. Leave to cool.
Grind down the lavender with a mortar and pestle.
Melt down the while chocolate, mix in the lavender and spread on top of each of the cakes.
Leave to set.
Cover one half with berry jam.
Place the second cake on top and it's ready to serve.